THE NERVOUS SYSTEM. 



So far as we have now studied the body we have its 

 framework and the muscles which are to give motion 

 to its various parts. We have learned how the mus- 

 cles act, and now comes the question : "What causes 

 them to act as they do? We have learned of the 

 obedience of the voluntary muscles to the will. But 

 how does the mind or will direct them token, how 

 much, and how long to_act? For the purpose of 

 enabling the mind to control the action of .the mus- 

 cles, a very interesting system of organs is provided 

 in the body, namely, the nervous system. This plate 

 gives us an excellent view of it. 



The brain is, in many respects, the most 



The Brain. . _ ,. _ r 1 



important organ of the body. It occu- 

 pies the loftiest chamber of the body house. (Raise 

 the face section and refer to the brain on plate. ) 

 Here the mind the invisible tenant or occupant of 

 the body seems to form its purposes and send out 

 its orders to its hundreds of servants stationed at as 

 many points, between top and toe. Here, also, it 

 receives its messages of intelligence from the body 



and from the outside world. These messages may 



(29) 



